Black Dividend

Original title: 夜の配当

Directed by Shigeo Tanaka

Ryokichi Ibuki is a clerk who learns company "top secrets" and becomes an industrial blackmailer. Kaoru Koizumi, a confidential secretary in love with Ibuki, reveals her firm's plans to him. She resigns when Ibuki blackmails her employer but Ibuki gains another spy in Ayuko Ichinoi...